1. Field of Invention
This invention relates generally to a total delivery system for supplying concentrated oxygen to a patient, and, more particularly, to a total delivery system including a portable oxygen concentrator for providing oxygen to ambulatory patients that can be interfaced with a stationary oxygen concentrator to provide additional oxygen capacity, power and sound dampening capability.
2. Description of the Related Art
Oxygen concentrators are frequently used as an unlimited source of oxygen for the treatment of patients who have had oxygen therapy prescribed by a physician, which is typically done to treat any of a variety of respiratory ailments and/or circulatory diseases. An oxygen concentrator typically uses a pressure swing absorption system to separate oxygen from the ambient air in the patient""s environment. A typical oxygen concentrator can provide a flow of oxygen ranging from 1 liter per minute to about 5 liters per minute depending upon the condition and needs of the particular patient receiving the concentrated oxygen. In can be appreciated that the higher the patient""s oxygen prescription, the more likely it is that the patient is bed-ridden or otherwise not ambulatory. Conversely, patients having relatively lower oxygen prescriptions, such as less than 3 liters per minute, are more likely to be ambulatory than a patient with a higher oxygen prescription.
The pressure swing absorption systems used in oxygen concentrators generally include molecular sieve beds for separating the gas mixture into an oxygen fraction and a nitrogen fraction. The oxygen fraction is provided to the patient while the nitrogen fraction is retained in the sieve bed and is subsequently purged. In a pressure swing absorption system, two sieve beds are utilized so that as one sieve bed separates nitrogen from the oxygen, the other sieve bed is simultaneously purged of the nitrogen absorbed during the prior separation cycle.
Typically, pressure swing absorption systems also include a compressor that draws air from the ambient environment and presents the air to the molecular sieves for separation of the gases. The type and size of compressor determines the overall oxygen flow rate capacity. Additionally, the compressor type and size are correlated to the level of noise produced by the system during operation. In general, large compressors required for providing higher rates of oxygen can be quite noisy, which may disturb the comfort of the patient and cause the patient to have difficulty sleeping while the compressor is operating.
Stationary oxygen concentrators have generally been used to supply oxygen to non-ambulatory patients or to ambulatory patients while they are resting or sleeping. Because stationary oxygen concentrators need not be moved, they can be constructed with large compressors and molecular sieves to provide a relatively high oxygen delivery capacity. Additionally, because stationary oxygen concentrators do not face size and weight constraints that are encountered when attempting to make a device portable, they can be constructed with substantial amounts of sound dampening insulation to muffle the compressor noise.
In contrast, portable oxygen concentrators have been developed to provide ambulatory patients with oxygen while they are traveling or moving about. It can be appreciated that it is desirable to keep the overall size and weight of a portable oxygen concentrator as small as possible, so that the concentrator may be easily transported. For this reason, portable oxygen concentrators generally have a relatively small oxygen delivery capacity, typically less than 3 liters per minute, which most likely suitable for ambulatory patients, i.e., patients with a relatively low oxygen prescription. While portable oxygen concentrators may include some sound dampening insulation, size and weight considerations generally dictate that they do not muffle compressor noise as efficiently as stationary oxygen concentrators.
As time passes, it is common for the condition of an ambulatory patient to worsen to the point where the patient requires additional oxygen capacity in excess of that supplied by a conventional portable oxygen concentrator. Typically, in these cases, the patient must then begin using a higher capacity stationary oxygen concentrator, incurring substantial costs and wasted resources in that the portable oxygen concentrator is no longer of use to such a patient. Similarly, ambulatory patients who need or desire the lower noise level of a stationary oxygen concentrator while sleeping, may also be required to obtain separate portable and stationary oxygen concentrators. The need for providing two concentrator systems to achieve the varied requirements, results in a higher cost to the patient or their insurer, health care provider, and/or reimbursement entity than would be encountered in buying either concentrator alone. Furthermore, durable medical goods suppliers must currently stock a number of both portable and stationary oxygen concentrators adequate to meet the demands of their clients, thereby incurring additional costs in maintaining their inventory.
Accordingly, it is an object of the present invention to provide a total delivery oxygen system that does not suffer from the disadvantages and/or shortcomings of conventional oxygen delivery systems.
It is a further object of the present invention to provide a total delivery oxygen system including a portable oxygen concentrator that can be combined with a low capacity stationary unit to provide additional oxygen capacity equivalent to that of a higher capacity stationary oxygen concentrator at a total cost substantially below that which would be required to provide a separate high capacity stationary oxygen concentrator.
The above objectives are accomplished according to the present invention by providing a total delivery oxygen concentration system having a first oxygen concentrating device that includes an air source for providing a flow of pressurized air derived from the ambient environment, a first primary molecular sieve for receiving the flow of pressurized air from the air source and for providing a first flow of oxygen enriched gas, a product tank disposed to receive the first flow of oxygen enriched gas from the first primary molecular sieve, and a valve for regulating the delivery of oxygen enriched gas from the first product tank to the end user. The total delivery oxygen concentration system also includes a supplemental oxygen concentrating device having a first supplemental molecular sieve for providing a second flow of oxygen enriched gas. In addition, a first pneumatic interface receives the second flow of oxygen enriched gas from the first supplemental molecular sieve and communicates the second flow of oxygen enriched gas to the product tank of the first oxygen concentrating device.
It is still another object of the present invention to provide a portable oxygen concentrator that can quickly and easily be docked with a base station, i.e., a supplemental oxygen concentrating device to provide augmented oxygen production. This object is achieved according to one embodiment of the present invention by providing a portable oxygen concentrating device capable of operating in conjunction with a supplemental oxygen concentrating device in a total delivery system. The portable oxygen concentrating device includes an air source and a first molecular sieve coupled to the air source to provide a first flow of oxygen enriched gas. In addition, a product tank is coupled to the first molecular sieve, and a first interface is coupled to the air source to provide pressurized air to a supplemental oxygen concentrating device. A second interface is coupled to the product tank to provide a second flow of oxygen enriched gas from the supplemental oxygen concentrating device to the product tank. In addition, a valve regulates the delivery of oxygen from the product tank to an end user.
It is yet another object of the present invention to provide a portable oxygen concentrator which can quickly and easily be docked with a base station for providing operational power or recharging the batteries of the portable concentrator as well as additional sound dampening insulation, or cooling capacity.
It is still another object of the present invention to provide a supplemental oxygen concentrating device capable of operating in conjunction with a first oxygen concentrating device in a total delivery system. According to a preferred embodiment of the present invention, the supplemental oxygen concentrating device includes a first molecular sieve that receives a first flow of pressurized air and provides a flow of oxygen enriched gas. In addition, a concentrated oxygen interface is coupled to the first molecular sieve that directs the flow of oxygen enriched gas from the first molecular sieve to a first oxygen concentrating device.
It is a further object of the present invention to provide a method providing oxygen enriched gas to a patient that does not suffer from the disadvantages of conventional oxygen concentration techniques. This object is achieved according to one object of the present invention by providing a method that includes providing a first oxygen concentrating device capable of outputting a first flow of concentrated oxygen, providing a supplemental oxygen concentrating device capable of outputting a second flow of concentrated oxygen, interfacing the first oxygen concentrating device with the supplemental oxygen concentrating device to combine the first and second flows of concentrated oxygen as a combined flow of concentrated oxygen. In addition, the method of the present invention includes directing this combined flow of concentrated oxygen to an end user, monitoring an inhalation state of the end user, and regulating the combined delivery of concentrated oxygen to the end user over a portion of the end user""s breathing cycle.
These and other objects, features and characteristics of the present invention, as well as the methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention.